Аннотация:Temperature dependence of the vaporization enthalpies were determined for some biphenyls. On the base of "double the differences" method the novel scheme for formation enthalpies of aromatic radicals calculations have been suggested. Using fundamental equations of the chemicals physics the new calculation method is offered to determine the energies of reorganization of molecules fragments into radicals, a namely biphenyl, biphenyl-oxide and phenyl-oxide are determined. REORGANIZATION ENERGIES OF THESE RADICALS AND BOND DISSOCIATION ENERGIES ARE CALCULATED.